SQLGetLobLength

SQLGetLobLength

SQLGetLobLength gets the length of the LOB pointed by the LOB locator obtained during the current transaction.

Syntax

SQLRETURN SQLGetLobLength(
    SQLHSTMT         stmt,
    SQLUBIGINT       locator,
    SQLSMALLINT      locatorCType,
    SQLUINTEGER *    valueLength);

Arguments

Data Type	Argument	In/Output	Description
SQLHSTMT	stmt	Input	A handle for the found results.
SQLUBIGINT	locator	Input	LOB Locator
SQLSMALLINT	locatorCType	Input	The C data type of A LOB locator. It can have the following values: - SQL_C_BLOB_LOCATOR - SQL_C_CLOB_LOCATOR
SQLUINTEGER *	valueLength	Output	It stores the length of a LOB. The buffer pointed to by the pointer returns the data length.

Return Values

SQL_SUCCESS
SQL_SUCCESS_WITH_INFO
SQL_INVALID_HANDLE
SQL_ERROR

Description

A function that is used to get the length of the LOB pointed by a LOB locator.

A LOB locator has the value that directly points LOB in a database (not offset in LOB). A LOB locator can be obtained in two ways:

It can be obtained from the LOB column in the result set of the SELECT SQL statement with SQLBindCol() or SQLGetData() function.

In this case, the application buffer type bound by the user should be SQL_C_CLOB_LOCATOR or SQL_C_BLOB_LOCATOR.

It can be obtained from the output parameter of SQLBindParameter().

In this case, the application buffer type bound by the user should be SQL_C_CLOB_LOCATOR or SQL_C_BLOB_LOCATOR.

If a LOB locator has not been obtained during the current transaction, it cannot be used as an argument for this function. This is because a LOB locator becomes invalid if a transaction is terminated. If an invalid LOB locator is used as an argument, this function will return SQL_ERROR, and the buffer pointed by the valueLength argument will not be changed.

The length of LOB is returned via the valueLength argument. However, If a LOB locator points NULL LOB, SQL_NULL_DATA is returned to the buffer pointed by the valueLength argument. If a LOB locator points NULL LOB, this function will not return an error.

Diagnosis

SQLSTATE	Description	Note
08S01	Communication link fault (Data transmission failure)	Communication link failed before function processing is complete between Altibase CLI driver and DB.
HY000	General error

Related Functions

SQLBindCol
SQLBindParameter
SQLFetch
SQLExecute
SQLGetLob
SQLPutLob

Example

It is assumed that a table has been created with the following DDL.

CREATE TABLE T1 (i1 INTEGER PRIMARY KEY, i2 BLOB);

Retrieve the length of LOB data

SQLINTEGER valueLength;
SQLUBIGINT lobLoc;
.
.
.
strcpy(query, "SELECT i2 FROM T1 WHERE i1=1");
if (SQLExecDirect(stmt, query, SQL_NTS) != SQL_SUCCESS)
{
    execute_err(dbc, stmt, "SQLExecDirect : ");
    SQLFreeStmt(stmt, SQL_DROP);
    return SQL_ERROR;
}

if (SQLBindCol(stmt, 1, SQL_C_BLOB_LOCATOR, &lobLoc, 0, NULL) != SQL_SUCCESS)
{
    execute_err(dbc, stmt, "SQLBindCol : ");
    SQLFreeStmt(stmt, SQL_DROP);
    return SQL_ERROR;
}

if (SQLFetch(stmt) != SQL_SUCCESS)
{
    execute_err(dbc, stmt, "SQLFetch : ");
    SQLFreeStmt(stmt, SQL_DROP);
    return SQL_ERROR;
}

if (SQLGetLobLength(stmt, lobLoc, SQL_C_BLOB_LOCATOR, &valueLength) != SQL_SUCCESS)
{
    execute_err(dbc, stmt, "SQLGetLobLength : ");
    SQLFreeStmt(stmt, SQL_DROP);
    return SQL_ERROR;
}

printf("SQLGetLobLength success!!!\n");

if (SQLFreeLob(stmt, lobLoc) != SQL_SUCCESS)
{
    execute_err(dbc, stmt, "SQLFreeLob : ");
    SQLFreeStmt(stmt, SQL_DROP);
    return SQL_ERROR;
}